Looking to upgrade my front axle. Found a used package locally that includes a lot of high quality outer stuff (knuckles,spindles,aisin hubs, brake rotors and calipers) and is offered with cromoly birfs and factory inners for a mini truck. Will this work?
Will 79-85 mini truck inner axles fit a 76-78 40 front end? (1 Viewer)
- Thread starter Elfman
- Start date
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RustyNailJustin
Supporting Vendor
Yes it will birfs out. You will need to do some minor grinding on the inside of your knuckle ball to fit those birfs (piece of cake). The inner shafts are different.
- Thread starter
- #3
Will the birfs fit on my inners? I'm not savvy on the differences of spline counts at the connections throughout the axle.
RustyNailJustin
Supporting Vendor
Factory inner (into the birf) is 27 spline. Cromo comes in both 27 spline and 30 so you will need to ask him what he has.
Inners AND birfs are different.
Inners are the wrong length.
Factory 76-78 birfs are LONGER than minitruck and 79+.
Factory 76-78 birfs are also slightly smaller in bell diameter....and you WILL need to grind your knuckles/axle opening for them to fit.
Inners are the wrong length.
Factory 76-78 birfs are LONGER than minitruck and 79+.
Factory 76-78 birfs are also slightly smaller in bell diameter....and you WILL need to grind your knuckles/axle opening for them to fit.
- Thread starter
- #6
found this really good break down while searching:
Toyota Land Cruiser FJ40/FJ55/FJ70 Chromoly Birfield Axle Guide and Comparison
All About Stock Toyota Birfields
Seems like the mini truck stuff should work with grinding inside the ball of the axle housing. ?
Toyota Land Cruiser FJ40/FJ55/FJ70 Chromoly Birfield Axle Guide and Comparison
All About Stock Toyota Birfields
Seems like the mini truck stuff should work with grinding inside the ball of the axle housing. ?
As Woody mentioned the birf length is different so when you put the chromo mini birfs in(assuming they are 27 spline as your inners are) you will find that you can not install the snap ring on the end under the locking hub. Search and you will find a solution that has been posted here on Mud alot. When you can not fit the snap ring you can use a specific size washer & the correct screw in end of birf to retain it from moving inward instead of the snap ring which can't go on due to the minor difference in length of stub shaft. Note: the 76-78 birf is an odd size and the above info. does not apply to all fj40's.
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If you swap all of this onto your axle housing with your inner axles you'll be in good shape (as long as those mini truck birfs are 27 spline inside). Then the birf length won't matter becuase it will match the knuckle/hub assembly and you get the stonger, better spindle/hub/brake. If you need to keep your current tie rod, there are tapered spacers to deal with that in the later steering arms.
- Thread starter
- #9
I did find the tapered spacers from Cruiser Outfitters. I will use those for now, since my 40 tie ends are practically brand new, and possibly upgrade to 80 ends and a custom tie rod later.
Hi Mud Members, I know this post is two years old but I am in this same situation. I am doing a brake upgrade on a 1970 fj with a 1976 fj. My only question is how do you know if you have ground enough of the inner ball to have proper clearance for the birfield to fit correctly? It fits right in when at 6 and 12 and if I hold it pretty straight it spins freely. how much is enough though? its pretty tight in there and do not want to have to pull in a part again. thanks in advance, Paul......
rkymtnflyfisher
Trout Bum
If it fits it ships.
pb4ugo
SILVER Star
The bushing inside the spindle centers the birf. This is why centering the knuckle will keep the inner axle in alignment with the inner seal and the birf centered in the ball.
